A. Field of the Invention
This invention relates to aromatic polyamides having a very high solubility in organic solvents such as in dimethylacetamide (DMAc) hexamethylphosphortriamide (HPT) and N-methylpyrrolidone (NMP).
B. Description of the Prior Art
Wholly aromatic polyamides with an all para orientation, such as the polyterephthalamide of paraphenylene diamine or 4,4'-di-aminobenzanilide are conventionally prepared by the low temperature solution polymerization techniques whereby an appropriate diamine(s) and acid halide(s) are reacted at low temperatures in a suitable organic solvent, such as, DMAc, HPT or NMP, to provide a solution of the polyamide (i.e. dope) which can be spun directly into fibers. Unfortunately, such polyamides exhibit poor solubility in these solvents even with added inorganic salts such as LiCl and, therefore, only dilute solutions of the polyamides are obtained (.ltoreq.10% polymer solids). Consequently, the spinning of these dopes into fibers involves the handling of very large quantities of solvent which renders fiber production via such dopes expensive and commercially unattractive.